The research for alternatives to substitute cement in concrete increased in the last years to reduce the environmental impact. Geopolymers or alkali-activated materials are one of the options. The proposed project aims to obtain a wet cell based on a geopolymer with alginate and natural fibres. The wet cell will be a final prototype composed of panels for wet construction areas such as bathrooms and kitchens. There is a lack of biobased solutions for wet areas currently in the market. And the present project, together with companies of suppliers and users from the market, aims to provide a solution for a wet cell using biobased materials. The natural fibres added to the geopolymer will substitute a portion of sand and gravel, producing a lighter product than concrete. Also, the fibres increase the thermal and acoustic insulation. Natural fibres should be pretreated to increase the bond with other materials in the mixture. The chemical used in the alkali-activated materials is the same to pretreat the fibres. Also, alginates extracted from seaweeds can be used as binders, and alkali is used in the extraction process. One of the objectives is to develop the method and technique to produce geopolymer with alginates and pretreat the fibre simultaneously during the mixture. After defining the optimum mixture for the geopolymer, panels will be produced, and in the end, a wet cell will be constructed with the geopolymer panels.